The final choice for the role of Thor came down to brothers Chris Hemsworth and Liam Hemsworth. Chris found it funny: "We both came all the way over here from Australia and ended up battling against each other." He however bore no ill-will towards Liam, claiming he was rooting for him to get the role.

Dr Selvig mentions a comrade who got mixed up with SHIELD, whom he described as "a pioneer in gamma radiation"; this alludes to Bruce Banner, whose experiments in gamma radiation mutated him into The Incredible Hulk (2008). A deleted scene also has him mention Hank Pym, also known as Ant-Man (2015).

Kenneth Branagh asked Anthony Hopkins to improvise his reaction to Thor's yelling at him in the banishment scene. Hopkins agreed, and when the scene was filmed many of the cast/crew present were sobbing. Chris Hemsworth and Tom Hiddleston later said they had to struggle to keep their composure during filming that scene. Hiddleston later complimented Hopkins, to which he said, "Ken's fantastic, isn't he?".

It's mentioned in passing that Thor's hammer was forged inside "a dying star". This actually makes a modicum of scientific sense. When a very large star dies in a supernova, sometimes its remains collapsed to form a "neutron star". These objects cram the mass of the sun into the size of a city, forming a new kind of matter nicknamed neutronium. A single teaspoon of this material would weigh billions of tonnes. If Mjölnir was made of this material, it would certainly explain its incredible weight.

Kenneth Branagh has been a fan of "Thor" since childhood. When Marvel Studios selected Branagh as the director, they sent him the complete collection of the Marvel Thor comics series as reference material for the character.

Anthony Hopkins claims he relates to his role of Odin: "I'm a little like Odin myself. He's a stern man. He's a man with purpose. I play the god who banishes his son from Asgard because he screwed up. He's a hot-headed, temperamental young man, probably a chip off of the old block... but I decide he's not really ready to rule the future kingdom, so I banish him. I'm harsh and my wife complains and I say 'That is why I'm king.'."

Tom Hiddleston described his role of Loki as "a comic-book, but nastier version, of King Lear's Edmund." In the William Shakespeare play, Edmund was a prince who was jealous of his brother Edgar and tricked his father into banishing him into exile.

To prepare for the role of Thor, Chris Hemsworth put on a massive amount of build and weight, through a six-month regimen of trips to the gym and indulging in a massive diet of eggs, chicken, sandwiches, vegetables, brown rice, steak and protein drinks.

Tom Hiddleston researched Marvel Comics' Loki and found him to be a multi-dimensional character, so based his performance as Loki on three different actors: Peter O'Toole (enigmatic reckless persona), Jack Nicholson (edgy and near-insane persona), and Clint Eastwood (persona with simmering anger).

According to Chris Hemsworth, the action coordinators experimented with different combat styles, but ultimately the fighting technique Thor utilizes is an original one, based on boxing: stance low to the ground, with big powerful hip movements.

Kenneth Branagh conceptualized this film as a Norse/comic-book twist on William Shakespeare's Henry V (1989), which was about a young king who underwent trials and tribulations: fighting a war, courting a girl from another land, trying to live up to the example set by his father (a beloved king), and basic character development.

The agent that grabs a bow and arrow when Thor is attempting to recover Mjölnir is referred to as Agent Barton. This is Clint Barton, also known as the archer Hawkeye, a Marvel hero who later appeared in The Avengers (2012).

Anthony Hopkins signed on as Odin despite never reading a "Thor" comic or knowing anything about the Thor mythology. It was the concept of the father and son relationship that intrigued him about the role.

Both Kenneth Branagh and Tom Hiddleston were performing in a West End stage production of 'Ivanov' when it was announced that Branagh would direct this movie. At the 2010 Empire Movie Con, Hiddleston recalled one night when, as a joke, he burst into Branagh's dressing room wielding an empty plastic container from a water cooler like Mjölnir, shouting "Come on, Ken, what do you think!?". Brannagh's response was reportedly a very jokey "You never know, darling, stranger things have happened". Two months later, Hiddleston was auditioning for Thor, before landing the role as Loki.

When Dr. Selvig is in the library looking at the book of Norse Mythology, there is an illustration of Odin walking across the Bifrost bridge with his Gungnir spear in one hand and the Tesseract in the other. In Captain America: The First Avenger (2011), the Red Skull mentions that the Tesseract was the jewel of Odin's treasure room.

According to Kenneth Branagh, the film's biggest challenge was connecting the worlds of Asgard and 21st century Earth: "It's about finding the framing style, the color palette, finding the texture and the amount of camera movement that helps celebrate and express the differences and distinctions in those worlds. If it succeeds, it will mark this film as different... The combination of the primitive and the sophisticated, the ancient and the modern, I think that potentially is the exciting fusion, the exciting tension in the film."

According to producer Kevin Feige, the Bifrost bridge is the films's most interesting set: "In the comics, it's literally a rainbow that extends out from Asgard and pops down on Earth. We're not necessarily doing that; we're not having the big hard solid lines of colors. We're saying it's some sort of energy, almost a solid quartz bridge that as the light catches it and flows through it, you get some of that rainbow-esque quality to it."

In Norse mythology Thor's nickname was "protector of mankind" (which is apt, considering Thor's superhero status today). Scandinavians until this day wears mjölnir-amulets, refereed to as "torshammare".

Alexander Skarsgård was one of the actors in the running for the role of Thor primarily for his physical appearance. Oddly enough, Alexander's own father Stellan Skarsgård landed a role in the film as professor Erik Selvig.

The film's portrayal of Thor combines the classic Marvel Comics character (Thor is cast down to earth to as punishment for his arrogance) with the Marvel "Ultimate" character (Thor is dismissed by many on earth as a crazy deluded man).

Natalie Portman took the role of Jane Foster because she couldn't resist the opportunity of a comic-book film directed by acclaimed director Kenneth Branagh: "I was just like Kenneth Branagh doing 'Thor' is super-weird, I've gotta do it."

To prepare of the role of Fandral, Josh Dallas drew inspiration from renowned swashbuckler Errol Flynn and his films: "Flynn had a lot of that boyish charm that Fandral's got all that in him." The comics' characterization of Fandral was also based on Flynn.

In the film, the casket of Ancient Winters was held by the Frost Giants of Jotunheim; in the comics it was held by the Dark Elves of Svartalfheim, in particular their leader Malekith the Accursed. In the film Loki holds the Casket and asks Odin if he is accursed, in homage to Malekith.

A model of the Infinity Gauntlet, an all powerful weapon capable of controlling aspects of reality (soul, time, space, power & mind) in the "Marvel Comics" universe, was constructed for this film. The model is made from bronze and copper (with jewels made from resin) and weighs 60 pounds. It was built to be operational so that animatronics could be built on it.

Originally, the persona of Dr Donald Blake (Thor's alternate identity/personality) was going to be in the film, and Kevin McKidd was considered for the part. However, Blake was written out, and was instead used as a false identity for Thor.

Thor's first arrival on earth, mirrors the happenings of Raiden's arrival to earth in the series Mortal Kombat: Legacy (2011). In both instances, a god of Thunder arrives to earth seemingly powerless and no one believing his claims. He ends up taken to a medical facility and kept drugged until he makes his escape.

Zachary Levi was approached for the role of Fandral, but had to turn it down due to scheduling conflicts. Dominic Cooper was rumored but Stuart Townsend was then cast in the role. But days before filming began he left the role because of creative differences with the filmmakers. Finally Josh Dallas took the role. Levi would later play Fandral in Thor: The Dark World (2013).

According to Kevin Feige, the filmmakers placed the Foo Fighters song "Walk" in the film because they thought its lyrics were strangely appropriate for the film: "If you asked two months ago if we would have a Foo Fighters song in this movie, I would have said I don't think so. But we heard the song, and it just has these eerie appropriate lyrics and themes. Ken in particular just loved it with these lyrics about learning to walk again and the way that fit the themes of the movie about redemption, learning to be a hero."

There is a billboard in the town advertising for New Mexico tourism with the slogan "Land of Enchantment - Journey into Mystery". "Land of Enchantment" is the nickname of New Mexico, "Journey into Mystery" is the title of the Marvel comic book where Thor made his debut (Journey Into Mystery #83).

The Science & Entertainment Exchange collaborated with the filmmakers on the film design and production with three physicists (Sean Carroll, Kevin Hand and Jim Hartle, as well as physics student Kevin Hickerson) to provide a realistic scientific background for the film. This collaboration resulted in changing Jane Foster's profession from nurse to physicist, and used the terminology "Einstein-Rosen bridge" (named after Albert Einstein and Nathan Rosen) to describe the Bifrost.

For his role as the warrior Volstagg, Ray Stevenson wore a specially designed fat suit that gave Volstagg a round but tough appearance: "What we've done is kind of sex Volstagg up... he's got every bit of that Falstaffian verve and vigour, and a bit of a beergut to suggest an enormous appetite, but he's not the Weeble-shaped figure in the comics. He's Falstaff with muscles!"

In April 2006, screenwriter and "Thor" fan Mark Protosevich wrote a script for the film, which he described as "an Old Testament God who becomes a New Testament God." However, the script was so laden with VFX-worthy sequences that it would require $300 million to film, so when Matthew Vaughn signed on, he rewrote and trimmed the script to bring the budget down to a more agreeable $150 million.

Jim Carrey was a long-time favorite and candidate for the role of Loki since The Mask (1994), which indirectly featured Loki (but put in more fame his magic powers). Josh Hartnett was also rumored for the role.

According to Don Payne, Jane Foster was more of a stereotypical scientist (dry and skeptical), but Natalie Portman wished to revise the character to make her more poetic: "She thought Jane could be someone who thinks outside of the box, someone whose theories are considered outlandish and are frowned upon by the scientific community. But it's the kind of thinking that leads to great discoveries. When Thor arrives, she's willing to take a leap of faith - and she has to pay the consequences for it."

In the film's audio commentary, Kenneth Branagh reveals that the shot near the very end of Jane Foster and her associates working in their lab was actually meant to be the opening shot of the film, and that the closing title sequence of the Nine Realms was originally planned to be the film's prologue.

When the SHIELD agents track the Asgardians in search of Thor, they spot Sif, Fandral and Hogun, but not Volstagg. A deleted scene has Volstagg knock out the SHIELD agents, having tracked them by their food, and then steal it.

The crater that is created by the impact of Thor's hammer is the same design as Captain America's shield. The center where the hammer rests is in the shape of a rough star, which then has two circles around it, clearly intended to be the stripes.

Walter Simonson:
a comic book writer/artist whose work on "Thor" was highly renowned and acclaimed, has a cameo appearance in the banquet scene near the end of the film, sitting between Sif and Volstagg.

In Iron Man 2 (2010), Thor's hammer Mjölnir was first seen lying in a crater in New Mexico. This was based on the comics (Fantastic Four #536), where in the aftermath of an apocalyptic event on Asgard, Mjölnir was cast out to land in Oklahoma, where it lay until Thor came to reclaim it.

The artifact that Nick Fury shows to Dr Selvig in the post-credits scene (which plays a major part in Captain America: The First Avenger (2011) and The Avengers (2012)) is the Tesseract, identified to be the the Infinity Gem of Space (a component of the Infinity Gauntlet). It is also based on the Cosmic Cube, a cube-shaped artifact of power.

When Thor gets back Mjolnir, for a brief second he is seen upright and surrounded by lightning. This is a homage to He-Man and the Masters of the Universe (1983), where Prince Adam's transformation into He-Man featured him in a similar position surrounded by lightning. Earlier on Thor also asked for a cat to ride - He Man rides a panther called Battle Cat.